Alert archive / Missouri / Mesoscale Discussions in 2011

Mesoscale Discussion 1273

June 18, 201135 counties in Illinois; 42 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Jun 18, 2011, 5:39 AM CDT for 35 counties in Illinois; 42 counties in Missouri. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued: Jun 18, 2011, 5:39 AM CDT (10:39 UTC)
Expired: Jun 18, 2011, 6:45 AM CDT
In force: 66 min
Issued by: the Storm Prediction Center

All 77 counties

Adams County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Clay County, IL, Clinton County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Gallatin County, IL, Greene County, IL, Hamilton County, IL, Jackson County, IL, Jefferson County, IL, Jersey County, IL, Johnson County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Perry County, IL, Pike County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Saline County, IL, Scott County, IL, Union County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Audrain County, MO, Bollinger County, MO, Boone County, MO, Callaway County, MO, Camden County, MO, Cape Girardeau County, MO, City of Saint Louis, MO, Cole County, MO, Crawford County, MO, Dent County, MO, Franklin County, MO, Gasconade County, MO, Iron County, MO, Jefferson County, MO, Knox County, MO, Lewis County, MO, Lincoln County, MO, Macon County, MO, Madison County, MO, Maries County, MO, Marion County, MO, Miller County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Osage County, MO, Perry County, MO, Phelps County, MO, Pike County, MO, Pulaski County, MO, Ralls County, MO, Randolph County, MO, Reynolds County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Shannon County, MO, Shelby County, MO, Warren County, MO, Washington County, MO, Wayne County, MO

The radar

The St Louis radar (KLSX), 9 km from the middle of the area, began a volume at 10:38 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 10.7 hours before the alert went out and 249 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 601 J/kg
Mixed-layer CIN: -46 J/kg
Mixed-layer LCL: 644 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 41 m²/s²
0-3 km storm-relative helicity: 27 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.9

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 18, 2:44 AM CDT	Severe Thunderstorm Watch	SPC	Bond, Calhoun, Clinton, Fayette, Greene, Jersey and 9 more	5 hr
Jun 17, 8:19 PM CDT	Severe Thunderstorm Watch	SPC	Barton, Bates, Benton, Camden, Carroll, Cass and 24 more	7 hr
Jun 17, 11:12 PM CDT	Mesoscale Discussion	SPC	Barton, Bates, Cass, Cedar, Henry, Jackson and 3 more	93 min
Jun 18, 2:07 AM CDT	Mesoscale Discussion	SPC	Bates, Benton, Buchanan, Caldwell, Camden, Carroll and 21 more	53 min
Jun 18, 9:39 AM CDT	Severe Thunderstorm Watch	SPC	Dunklin, Pemiscot	7 hr
Jun 18, 3:34 PM CDT	Mesoscale Discussion	SPC	Barton, Bates, Benton, Cass, Cedar, Dade and 8 more	116 min
Jun 18, 6:03 PM CDT	Severe Thunderstorm Watch	SPC	Barry, Barton, Bates, Benton, Carroll, Cass and 28 more	10 hr

Nearby

Mesoscale Discussions in Missouri, 2011 Mesoscale Discussions in Illinois, 2011 Every mesoscale discussion in 2011

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.